1. Field of the Invention
The invention relates to a pair of spectacles, more particularly to a pair of spectacles with an eye-protecting piece that can be connected easily and securely to a frame member and that can be adjusted angularly relative to the frame member.
2. Description of the Related Art
Referring to FIG. 1, a pair of conventional spectacles is shown to comprise an eye-protecting piece 2 to be disposed in front of the user's eyes and a U-shaped frame member 1 to be provided around an upper edge portion of the eye-protecting piece 2.
The eye-protecting piece 2 includes an elongated transparent plate 20 with two opposed ends and an upper edge portion which is formed with a through-hole 25 between the opposed ends, and a pair of side plates 21 which extend symmetrically from the opposed ends of the transparent plate 20, thereby forming two free end portions 210. Each of the side plates 21 has an upper section with a top edge, a slot 22 formed through the upper section and extending toward a lower section of the side plates 21, and a row of dents 23 formed on an outer surface of the upper section and located between the slot 22 and a corresponding one of the free end portions 210. Note that the dents 23 are staggered with one another.
The U-shaped frame member 1 has an elongated intermediate portion 11 with a protuberance 16 and two side portions 12 which extend from two opposed ends of the intermediate portion 11. Each of the two side portions 12 has an engaging lug 13 with an enlarged head 130 and a boss 14 adjacent to the engaging lug 13. A pair of legs 15 are mounted pivotally and respectively to the free ends of the side portions 12.
Referring to FIGS. 2 and 3, the eye-protecting piece 2 is disposed vertically while the U-shaped frame member 1 is placed uprightly on two sides of the side plates 21 of the eye-protecting piece 2. Under this condition, the enlarged heads 130 can pass through the slots 22, and the U-shaped frame member 1 can be pivoted about the engaging rods 13 with respect to the transparent plate 20 such that the enlarged heads 130 are disposed across the width of the slots 22 while the bosses 14 extend selectively into one of the dents 23, thereby preventing the U-shaped frame member 1 from disengaging the eye-protecting piece 2. After the eye-protecting piece 2 and the U-shaped frame 1 have been connected, the slots 22 permit a slight movement of the engaging rods 13 therein. The intermediate portion 11 of the U-shaped frame member 1 is pushed towards the eye-protecting piece 2 so that the protuberance 16 engages in the through-hole 25 in the eye-protecting piece 1.
Note that in the above-mentioned conventional spectacles, the enlarged heads 130 of the engaging rods 13 can only prevent the eye-protecting piece 2 from disengaging the U-shaped frame member 1. The positioning of the eye-protecting piece 2 on the frame member 1 is performed by a combined action of the extension of the protuberance 16 in the through-hole 16, and the bosses 14 in one of the dents 23. Since the bending inward action of the side plate 21 relative to the transparent plate 20 is prevented by the enlarged heads 130 of the engaging lugs 13, a clearance 26 may formed between the side plates 21 of the eye-protecting piece 2 and the side portions 12 of the frame member 1 after a period of use. This consequently causes loose engagement between the bosses 14 and the dents 23 and eventually leads to poor angle adjustment between the eye-protecting piece 2 and the frame member 1.